간행물
한국도로학회논문집 KCI 등재 International journal of highway engineering
- 발행기관 한국도로학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1738-7159 (Print)2287-3678 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 토목공학 공학 분류의 다른 간행물
- 십진분류KDC 534DDC 625
권호리스트/논문검색
제25권 제6호 (2023년 12월) 44건
1.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The current research aims to evaluate the impact of coating materials and temperature on the percentage of bead loss in pavement markings. METHODS : Five mixtures with varying numbers of coating layers (C0, C1, C2, C3, and C4) were prepared to assess the effect of coating layers on bead loss. The effect of stripping was simulated using a modified Hamburg Wheel Tracking test. Furthermore, the influence of temperature and coating material on bead loss was examined using control mixture (without coating), YR, and SY coating mixtures. The percentage bead loss was evaluated by a developed image analysis program. RESULTS : The results demonstrated a substantial reduction in bead loss as the number of coating layers increased, with the C4 mixture showing an impressive 4.3% bead loss after 500 HWT braking cycles compared to 27.4% for the C0 mixture. Higher testing temperatures resulted in increased bead loss, with the control mixture exhibiting the highest percentage loss at 7,500 HWT rolling cycles. Conversely, the YR and SY coating mixtures displayed superior resistance to bead loss. Statistical analysis confirmed the significance of coating layers in reducing bead loss, further supporting the effectiveness of coatings in preserving bead adhesion during HWT cycles. CONCLUSIONS : The findings highlight the potential of coating materials as a key protective measure for enhancing the longevity and performance of pavement markings.
4,000원
2.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : LED based Variable Message Signs(VMS) have been widely used to inform safety messages to the drivers in advance. Legibility Distance of VMS is the most important factor to provide the safety messages to drivers in timely and effective way. However, current National Standards on legibility distance design considers letter size only even there is a difficulty to read the signs at adverse weather conditions such as heavy fog. So, this study examined the legibility issue under fog by evaluating the legibility distance with two design factors such as letter size and luminance. METHODS : Two foggy weather conditions, intermediate and heavy fog, were simulated at real-road-scale Proving Ground. Legibility distance at daytime and nighttime was evaluated by test subjects. Subjects were asked to fill the legible distance on the test sheet and statistical significant was analysed at the lab. RESULTS : The legibility distance(LD) under fog was observed only 22 to 41% of LD observed under normal weather condition at daytime, and 26 to 45% at nighttime condition. Study results showed a consistent increase in LD with higher luminance even at same letter size and vice versa conditions, However, statically significant difference between groups was only revealed when both letter size and luminance level increased conditions. In order to apply the test results in terms of engineering benefits, LD results from significantly different groups was evaluated with relative to Stopping Sight Distance(SSD) within conceptual frame suggested in this study. CONCLUSIONS : From the study results, current National Standard on legibility distance design needs to consider letter size and luminance simultaneously to response the legibility issue in adverse weather conditions.
4,000원
3.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to investigate the tendency of material property estimation under different concrete distress conditions and curling conditions when non-destructive tests such as rebound hammer and surface deflection test are applied to concrete pavement. METHODS : Nondestructive tests using Schmidt hammer and Falling Weight Deflectometer were performed to inspect the expressway concrete pavements constructed more than 20 years ago. Some results were compared with core tested elastic modulus and compressive strength. RESULTS : As a result of the rebound test, the section with Alkali-Silica Reaction(ASR) distress was outside the range of the existing estimation formula, but the control section was found to be within the range of the existing estimation formula. As a result of the physical property estimation through deflection test, the section with ASR distress showed greater fluctuations in the estimated material properties and deflection ratio compared to the control section, showing that the ASR damage seems to affect the slab deflection behavior. CONCLUSIONS : The rebound test may not sufficiently reflect the decline in material properties due to concrete damage. The deflection test can obtain results that reflect the deterioration of material properties, but it was confirmed that significant variability may occur, so it seems to necessary to perform complementary indoor core tests with nondestructive testing(NDT) tests.
4,000원
4.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : Safety Evaluation of Wind Loads of Renewable Energy and Photovoltaic Power Structures. METHODS : Structural safety evaluation was conducted on the wind load of 3kW Photovoltaic Power Structures using ABAQUS. Wind speed was reviewed for 36m/s and 60m/s. Effective Mass and Mass Contribution of Photovoltaic Power Structures was utilized up to 90%. 7 steps were set and applied to structural analysis. RESULTS : As a result of the structural analysis, it was confirmed that the long-term blowing load was affected rather than the size of the wind load. Weak areas were identified at the point of the horizontal beam rather than the modules of the Photovoltaic Power Structures. In particular, it was confirmed that stress exceeding the allowable stress was generated at the junction. In order to secure the safety of Photovoltaic Power Structures, it is judged that reinforcement of the branch is necessary. CONCLUSIONS : The safety of Photovoltaic Power Structures structures for wind load is influenced by persistence rather than the size of the wind load. Therefore, in order to prevent this, it is judged that reinforcement of the branch is necessary.
4,000원
5.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : Experimental findings pertaining to the mechanical properties and microstructures of calcium sulfo-aluminate (CSA) cement and amorphous calcium aluminate (ACA) cement based-repair mortars incorporated with anhydrite gypsum (AG) are described herein. METHODS : To prepare the mortars, the CSA or ACA as binders were adopted and the ratio of water–binder was fixed at 0.57. For comparison, mortar made of Type I ordinary Portland cement (OPC) was prepared. The fluidity, setting time, compressive and bond strengths and absorption of the mortars were measured at predetermined periods. In addition, the microstructures of paste samples using OPC, CSA or ACA were visually examined through SEM observation. RESULTS : The ACA-based mortars showed the increases in the fluidity, and the acceleration of the setting time. Furthermore, the ACAbased binder effectively enhanced the compressive and bond strengths of the mortars owing to amount of formation of C2AH8 hydrates. Meanwhile, the mortar with ACA showed an excellence absorption. CONCLUSIONS : Comparing with those of CSA-based mortars, the mechanical properties of ACA based-mortars were more remarkable. However, further studies regarding the durability of repair mortars using aluminate-based binders must be conducted to obtain the optimal mixture.
4,000원
6.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study intended to derive a methodology that can evaluate water splash caused by distress on the road surface based on experimental methods and to present quantitatively by analyzing the impact on road users. METHODS : Through literature review, the current problems of road pavement and drainage facility standards, the factors of road splash caused by puddle was selected to measure damage. Field measurements were conducted by setting different conditions for each factors and setting different conditions based on the hypothesis. In addition, water splash by surface distress type and puddle was measured to analyze using statistical techniques from correlation to multi-regression. RESULTS : The maximum and effective distance due to road splash increases as the driving speed, regardless of vehicle load and tyre type. Splash was measured according to the type of road distress to analyze the correlation between the influencing factors, and there was a weak correlation between the width and length of the puddle, depth and the effective distance. In addition, the interaction analysis showed that there was an interaction between the width of the water hole and the depth of puddle. Moreover, based on the multi-regression analysis, it was not statistical significant. This is judged to that the number of data samples used for this analysis is limited because the diversity of puddle conditions cannot be set differently for each type of distress. CONCLUSIONS : Since the distress of depending on the size, depth and shape of the road surface, it is necessary to calculate it and present maintenance standards, so this results present an experimental methodology that can intuitively evaluate damage cased by unestablished puddle. From this results, this is expected to be used as a quantitative indicator to evaluate the satisfaction of road users as a functional performance according to road surface condition.
4,200원
7.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to conduct basic research on the development of repair materials for cross-sectional repair of the concrete of the lower slab ceiling of an old bridge. METHODS : To estimate the performance as restoration materials, cross section rebound test, compressive strength test, flexural strength test, and firing shrinkage test was done. Rebound test was done by weight of amount of rebound and weight of concrete accumulated in frame. Cross section rebound test was done by put ruler in the deepest part of concrete stick on frame. Compressive and flexural strength test was done based on KS F 2405 and KS F 2408. Firing shrinkage test was done based on ASTM C 1579-16. RESULTS : As a result of the experiment, an appropriate bonding thickness was secured by mixing natural fibers, polymers, early steel cement, and expansion materials, and the dust reducing agent was excluded due to the problem of lowering compressive strength. In addition, the amount of rebound was reduced by using a hydro mix nozzle, and plastic shrinkage cracks were also reduced due to the internal curing effect of natural fibers. CONCLUSIONS : This study was a basic study in the development of repair materials for cross-sectional repair of the lower ceiling of an aged bridge slab, and developed a material with appropriate performance. However, there is a problem that the amount of rebound and dust increases depending on the type of cement, so experiments will be conducted by changing the type of cement in future research.
4,000원
8.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This research assesses the influence of emulsified asphalt on vegetation growth by examining parameters such as moisture content, temperature, pH, electrical conductivity, and analyzing the extent of green coverage using image analysis. METHODS : Within this study, sensors were employed to measure the growth environment of vegetation treated with emulsified asphalt. Furthermore, the analysis of the greening rate through image analysis has been incorporated. RESULTS : Research indicates that emulsified asphalt effectively secures seeds to surfaces and maintains moisture content for an extended period. However, the excessive utilization of emulsified asphalt has been observed to reduce germination and greening rates. CONCLUSIONS : The application of an optimal emulsified asphalt content is presumed to promote vegetation growth. To establish objective, it is imperative to conduct comprehensive research on its long-term structural effects regarding growth, greening rate, and slope when integrated with emulsified asphalt.
4,000원
9.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to verify the influences on the compactibility evaluation of WMA (Warm Mix Asphalt) mixture by laboratory experiments. METHODS : Two types of WMA additives (chemical and wax types) and two types of compactors (marshall and gyratory) are used in laboratory experiments. In addition, two types of WMA processes (wet and dry) are tested to verify the impact of manufacturing process. RESULTS : The laboratory results show that the effects of compaction method on compactibility are different depending on the type of additive. The compaction method has a significant impact on WMA mixture with chemical type additive to extent that it determines whether required criterion is satisfied, but only little on WMA mixture with wax type additive. In the case of wet process for WMA mixture manufacturing, it is hard to assess the air void of HMA mixture made of same asphalt binder used in WMA mixture since the additive has already been added in asphalt binder. And the test results show that air voids of HMA mixture vary within properties of asphalt binder. CONCLUSIONS : Through this study, it is found that compactibility of WMA mixture is affected by the compaction methods depending on the additive types and by the WMA mixture manufacturing process. Therefore, those are recommended to be considered when evaluating compactibility of WMA mixtures.
4,000원
10.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study was conducted to investigate the stress distribution and resulting effects in the joint between CRCP and JCP when temperature deformation occurs. METHODS : The tie bars, CRCP and JCP pavements, and lean concrete base were created as three-dimensional finite element models using ABAQUS, a general-purpose finite element analysis program. Contact stress analysis was performed between rebar and JCP and between JCP and lean concrete base layer. In the section where stress concentration occurred, the degree of damage was estimated using the CDP model. RESULTS : Since the domestic CRCP does not have a separation layer between the base layer and the surface layer, it was found that when connected to a JCP where the base layer and the surface layer are completely separated, stress concentration occurs around the tie bar at the connection point. Analysis results using the CDP model showed that 25 to 32 mm around the reinforcing bar exceeded the elastic range of concrete. CONCLUSIONS : At the point where CRCP and JCP are connected, local stress concentration is inevitable because the friction and bonding conditions with the base layer and the degree of curling deformation restraint by CRCP rebars are different, and design improvement is expected through life cycle cost and long-term measurement analysis.
4,000원
11.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : In this study, the resources and energy consumed to produce hot mix asphalt mixtures and hot mix reclaimed asphalt mixtures in asphalt concrete plants were estimated and the emissions from the detailed processes of the production process were evaluated based on TRACI(the tool for the reduction and assessment of chemical and other environmental impacts). METHODS : To estimate the energy consumption of the aggregate drying process, which consumes a significant amount of energy in the production process, an energy consumption calculation model based on the thermal equilibrium equation was used, and the energy consumed for material transportation, storage, and operation of other facilities was cited from the literature. RESULTS : For the system boundary conditions established and the inventory considered, the emissions to produce one ton of hot mix reclaimed asphalt mix are greater than the emissions to produce one ton of hot mix asphalt mix for a number of key impact categories. The process of producing hot mix reclaimed asphalt mixtures was evaluated to consume more resources and energy in the production of recycled aggregates and heating for drying than in the production of hot mix asphalt mixtures, but less resources and energy in the production of binders and natural virgin aggregates and the heating to heat these materials. CONCLUSIONS : The results of the emissions assessment using the life cycle inventory for the production of hot mix asphalt mixtures were generally similar to the results understood in the field and in much of the literatures, confirming the reliability of the methodology. However, in order to evaluate the dominance of specific processes or mixtures, it is believed that the construction of a wide range of inventory databases after inventory redesign is necessary for a specific and rigorous assessment.
4,000원
12.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to verify the effect of improving the retroreflectivity of pavement marking by increasing the refractive index of glass bead. METHODS : Pavement marking test-beds has been installed in National Highway 19, 42 and KICT Yeoncheon SOC Center. In testbeds several marking sections were installed for each type of marking materials and glass beads. In this test-beds initial dry and wet retroreflectivity were measured and analyzed. RESULTS : When the refractive index of glass bead was adjusted upward in water based paint(glass bead No.1→ No.2), dry retroreflectivity increased by about 30 to 70%, and wet retroreflectivity slightly increased by about 10 to 40%. When using glass bead No. 2 in water based paint, it was found to meet the standards of the Road Traffic Act. However, since wet retroreflectivity of water based paint slightly exceeds the standard value, a follow-up investigation is needed to determine how long this performance can be maintained. When using glass bead No.1 in MMA(methyl methacrylate), the average wet retroreflectivity was evaluated to be 128 to 150 mcd/lx/m2, and when using glass bead No.2, the average wet retroreflectivity was evaluated to be about 200 to 270 mcd/lx/m2. Accordingly, MMA showed the best performance compared to other paints. CONCLUSIONS : When using glass bead No.1 in water-soluble paints and thermoplastic, it did not meet the wet retroreflectivity standards of the Road Traffic Act. But when using glass bead No.2, it met the wet retroreflectivity standards. As a result of analyzing the road marking budget according to the upward adjustment of the refractive index of glass bead, it was analyzed that if only the material class was adjusted upward, the cost would increase by more than twice the current budget. In order to decrease this budget increase rate(to increase service life), it is necessary to strengthen quality control standards for pavement marking and develop scientific-systematic quality control techniques.
4,000원
13.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The number of snowfall and the amount of snowfall are gradually increasing, and due to the characteristics of Seoul, which has a lot of traffic, it is difficult to respond quickly with a snow removal method that relies on snow removal vehicles. Therefore, it is necessary to develop an IoT based eco-friendly snow removal system that can respond to unexpected heavy snow in winter. In this study, the low temperature operation and snow removal performance of the IoT road condition snow removal detector and the snow removal system using CNT and PCM are evaluated in the climatic environment chamber. METHODS : To make artificial snow, it consists of an climatic environment chamber that can simulate a low temperature environment and equipment that can supply compressed air and cold water. Depending on the usage characteristics of the climatic environment chamber, use an air-water type snow maker. In order to make artificial snow, wet temperature, which takes into account the actual air temperature and the amount of moisture in the air, acts as the most important variable and is suitable for making snow, below –1.5 ℃. The lower the water temperature, the easier it is to freeze, so the water source was continuously supplied at 0 ℃ to 4 ℃. One of the two different pipes is connected to the water tank to supply water, and the other pipe is connected to the compressor to supply high-pressure air. Water is dispersed by compressed air in the form of many small droplets. The sprayed microscopic water particles freeze quickly in the low temperature environmental climatic chamber air and naturally fall to the floor, forming snow. Based on the KS C IEC 60068-2-1 cold resistance test standard, an integrated environmental test procedure was prepared to apply to IoT-based snow removal systems and performance evaluation was performed accordingly. The IoT based eco-friendly snow removal system is needed to in winter, so visual check and inspect the operation at the climatic chamber before setting up it to the actual site. In addition, grid type equipment was manufactured for consistent and reliable snow removal performance evaluation under controlled environmental conditions. RESULTS : The IoT-based eco-friendly snow removal system normally carried out the task of acquiring data and images without damaging the appearance or freezing in a low temperature environment. It showed clear snow removal performance in areas where PCM and CNT heating technology were applied to the concrete slab. This experiment shows that normal snow removal tasks can be carried out in low temperature environments in winter. CONCLUSIONS : The integrated environmental test procedures and grid type evaluation equipment are applied to low temperature operation and snow removal performance evaluation of snow removal systems. In the climatic environment chamber, where low temperature environments can be simulated, artificial snow is created regardless of the season to derive quantitative experimental results on snow removal performance. PCM and CNT heating technology showed high snow removal performance. The system is expected to be applied to road site situations to preemptively respond to unexpected heavy snow in winter.
4,000원
14.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : Construction cost estimates are important information for business feasibility analysis in the planning stage of road construction projects. The quality of current construction cost estimates are highly dependent on the expert's personal experience and skills to estimate the arithmetic average construction cost based on past cases, which makes construction cost estimates subjective and unreliable. An objective approach in construction cost estimation shall be developed with the use of machine learning. In this study, past cases of road projects were analyzed and a machine learning model was developed to produce a more accurate and time-efficient construction cost estimate in teh planning stage. METHODS : After conducting case analysis of 100 road construction, a database was constructed including the road construction's details, drawings, and completion reports. To improve the construction cost estimation, Mallow's Cp. BIC, Adjusted R methodology was applied to find the optimal variables. Consequently, a plannigs-stage road construction cost estimation model was developed by applying multiple regression analysis, regression tree, case-based inference model, and artificial neural network (ANN, DNN). RESULTS : The construction cost estimation model showed excellent prediction performance despite an insufficient amount of learning data. Ten cases were randomly selected from the data base and each developed machine learning model was applied to the selected cases to calculate for the error rate, which should be less than 30% to be considered as acceptable according to American Estimating Association. As a result of the analysis, the error rates of all developed machine learning models were found to be acceptable with values rangine from 17.3% to 26.0%. Among the developed models, the ANN model yielded the least error rate. CONCLUSIONS : The results of this study can help raise awareness of the importance of building a systematic database in the construction industry, which is disadvantageous in machine learning and artificial intelligence development. In addition, it is believed that it can provide basic data for research to determine the feasibility of construction projects that require a large budget, such as road projects.
4,000원
15.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study is aimed to economic analysis of the ferronickel slag pavement method carried out to suggest the necessity of developing ferronickel slag pavement technology. METHODS : A life cycle cost analysis of the application of the Ferronickel Slag pavement method and the cutting + overlay pavement method was performed to compare the economic indicators and greenhouse gas emissions for each pavement method. RESULTS : As a result of the analysis, regardless of the Ferronickel Slag mixing rate, if the common performance of the Ferronickel Slag pavement method is the same or superior to the existing pavement method, it is more economical than the existing pavement method. Furthermore, the lower the maintenance cost of the Ferronickel Slag pavement method, the higher the economic feasibility due to the high Ferronickel Slag mixing rate. Greenhouse gas emissions can be reduced from at least 9% to up to 53% through the application of the Ferronickel Slag pavement method, except for some scenario analysis results. CONCLUSIONS : This study provided that the Ferronickel Slag pavement method was superior to the existing pavement method in terms of economic and environmental aspects. Therefore, it was found that the objective justification of developing road pavement technology using Ferronickel Slag was secured.
4,000원
16.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study aims to conduct a laboratory evaluation on the use of ferronickel slag for manufacturing Hot Mix Asphalat mixtures. METHODS : This research was based on laboratory evaluation only, where conventional aggregate and FNS at a ratio of 7:3 were used in HMA and the volumetric properties, physical and mechanical properties, and long-term performance of FNS in asphalt mixture were evaluated. RESULTS : The overall results showed that FNS can be applied as aggregate in a hot mix asphalt since volumetric, physical and mechanical properties and long-term performance of HMA mixture with ferronickel slags as aggregate met the required standards according to Korean standards for Asphalt Concrete. CONCLUSIONS : The tensile strength ratio results of HMA mixtures with ferronickel aggregate did not meet the required standards, yet the addition of anti-stripping agent and waste glass fibers to the HMA mixture with ferronickel slags improved the tensile strength results to meet the standards. Additionally, compared to the HMA mixture of the same aggregate gradation but with only natural aggregate, HMA mixture with ferronickel slags had almost the same results for the majority of tests conducted.
4,000원
17.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : There has been increasing interest in South Korea on warm-mix asphalt (WMA) and cold-mix asphalt (CMA) technologies that allow production of asphalt pavement mixtures at comparatively lower temperatures than those of hot-mix asphalt (HMA) for use in pavement engineering. This study aims to evaluate the feasibility of replacing HMA pavement with WMA pavement with the goal of reducing CO2 emissions associated with asphalt production for road construction. METHODS : Changes in the dynamic modulus characteristics of WMA and HMA according to short-term and long-term aging were evaluated. In addition, the effects of water damage were evaluated for short- and long-term aging stages. RESULTS : For WMA, in the process of mixing and short-term aging, early-age dynamic modulus decreased owing to low temperature and reduced short-term aging (STA) time. This could result in early damage to the asphalt pavement depending on the applied traffic load and environmental load. CONCLUSIONS : Mastercurves of the dynamic modulus were used for comparative analysis of WMA and HMA. Compared to the dynamic modulus after STA of HMA, the estimated aging time determined by experiments for WMA to achieve the required stiffness was more than 48 hours, which is equiva-lent to approximately 4 to 5 years real service life when converted. It is considered that further studies are needed for performance optimization to achieve early-age performance of the asphalt mixes.
4,000원
18.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to statistically analyze the meteorological factors that contribute to the formation of road surface icing based on actual cases of icing accidents and provide directions for improving icing evaluation criteria. METHODS : In this study, we collected cases of domestic road icing accidents by searching news articles with the keyword ‘icing collision accidents’. Subsequently, we determined the latitude, longitude, and altitude of accident locations using satellite map service. We applied the Inverse Distance Weighting (IDW) method and temperature lapse rate to estimate meteorological data at each location. Finally, statistical analysis was conducted for temperature, humidity, and precipitation occurrence using probability density functions. RESULTS : As a result, road icing accident data points with identifiable location coordinates were collected. Among these, temperature, humidity, and precipitation occurrence from Automated Weather Stations (AWS) data were selected for analysis. During the process of correcting meteorological factors using the Inverse Distance Weighting (IDW) method, the optimal Weighting Exponent (p) that minimizes the error was determined and applied. The results showed that accidents occurring in the morning indicated the highest accident occurrence rate. The average temperature at the time of the accidents was -1.4°C, with a humidity level of 85.1%. Precipitation was observed at the time of the accident in 19 cases. CONCLUSIONS : Icing on pavement can occur not only under extreme weather conditions but also under typical meteorological conditions. Typically, icing can occur when the relative humidity is above 70%. Accordingly, for future improvements in the evaluation criteria for icing-prone areas by the Ministry of Land, Infrastructure and Transport, it is possible to incorporate the temperature and humidity ranges that generally lead to icing, taking into account climate characteristics.
4,000원
19.
2023.12
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study was conducted to evaluate the physical properties of the RAP 50 asphalt mixture containing polymer modified rejuvenator and warm-mix additive to improve the recycling rate of RAP and reduce CO2 emission. METHODS : Mix design of Polymer Modified Warm-mix Asphalt Mixture(RAP 50), and Hot Mix Asphalt Mixture(RAP 30) were produced and the properties of asphalt mixture such as Marshall Stability, ITS, Deformation Strength, TSR, and Dynamic Stability were compared between the two asphalt mixtures. RESULTS : The RAP 50 asphalt mixture showed superior or similar performances compared to the RAP 30 asphalt mixture in all the tests conducted. The results of the Marshall stability and dynamic stability in particular were 13,045N and 3,826 pass/mm, which were 11.37% and 76.7% greater than the RAP 30 asphalt mixture, which indicated that high plastic deformation resistance may be expected. CONCLUSIONS : The results obtained from laboratory tests on the two types of mixtures indicated that the use of polymer modified rejuvenator and warm-mix additive not only allows to increase the proportion of RAP but also improves its properties under lower temperature condition than RAP 30 asphalt mixture. Additionally, it was confirmed that plastic deformation resistance was high and moisture resistance and crack resistance were improved for a RAP 50 asphalt mixture.
4,000원
20.
2023.12
구독 인증기관 무료, 개인회원 유료
algorithms for deriving and analyzing retroreflectivity influence factors through regression analysis. METHODS : An experimental road lane was created to examine the trends of retroreflectivity and LiDAR intensity values, and a controlled indoor experiment was conducted to identify influencing factors. The optimal algorithm was developed by regression analysis of the experimental data. RESULTS : The significance probability (P-value) through SPSS linear regression analysis was 0.000 for measured height, 0.001 for perpendicular angle, 0.157 for vertical angle, and 0.000 for LiDAR intensity, indicating that measured height, vertical angle, and LiDAR intensity are significant factors because the significance probability is less than 0.05, and vertical angle is not significant. The NNR regression model performed the best, so the measurement data with height (1.2m, 2m, 2.2m) and vertical angle (11.3°, 12.3°, 13.5°) were analyzed to derive the optimal LiDAR Intensity measurement height and vertical angle. CONCLUSIONS : For each LiDAR measurement height and vertical angle, the highest correlation between LiDAR Intensity and retroreflectivity was found at a measurement height of 1.2 meters and a vertical angle of 12.3°, where the model learning accuracy (R2) was the highest.
4,000원
